Patterns of metastases of prostatic ductal adenocarcinoma

Background: The current study was conducted to investigate the patterns of metastases in men with metastatic prostatic ductal adenocarcinoma (DAC) and recurrence patterns after therapy. Methods: All patients with a new diagnosis of DAC with de novo metastases and those with localized disease who developed metastases after treatment and were treated at the study institution from January 2005 to November 2018 were included. All patient and tumor characteristics and outcome data were collected. Results: A total of 164 patients (37.7%) had metastatic DAC, including 112 with de novo metastases and 52 who developed metastases after treatment. Men with de novo metastases were found to have a significantly higher median prostate-specific antigen level and International Society of Urological Pathology grade but a lower cT3 and/or T4 classification compared with those with metastases that developed after treatment (all P <.05). Approximately 87% of men with de novo metastases progressed despite multiple systemic therapies, 37.6% required intervention for the palliation of symptoms, and 10.1% responded to systemic therapy and underwent treatment of the primary tumor. Men with de novo metastatic DAC and those who developed metastases after treatment had multiple metastatic sites (including bone and viscera), with higher rates of lung metastases noted in the posttreatment group (23.2% vs 44.2%; P =.01). A total of 45 patients who were treated with curative intent developed metastases at a median of 22 months (range, 0.9-74.8 months) after treatment, at low prostate-specific antigen levels (median, 4.4 ng/mL [interquartile range, 1.7-11.1 ng/mL]). Conclusions: The current study described the metastatic patterns of DAC in both patients with de novo metastatic disease and those who later progress to metastases. Men receiving treatment for DAC with curative intent require stringent long-term follow-up with imaging modalities, including chest imaging given the predilection toward lung metastases noted among these patients.